Operating mechanism



Jan. 19, 1937. J. LINDE 5 OPERATING'MECI-IANISM Filed Dec. 28, 1934Fig.2.

Inventor: Leonar'dlLinde,

is Attorn ey.

DISTANCE Patented Jan. 19, 1937 PATENT OFFICE OPERATING MECHANISMLeonard J. Linde, Aldon, Pa., assignor to General Electric Company, acorporation of New York Application December 28, 1934, Serial No.759,555 11 Claims. (01. 200-89) My invention relates to operatingmechanisms, more particularly to operating mechanisms of the trip-freetype wherein means are provided for rendering ineffective the operatingforce during any part of the operating stroke, and has for its principalobject the provision of an improved operating mechanism of the aforesaidtype which is efficient and positive in operation,

simple and compact in design, and inexpensive.

in construction.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming apart of this specification.

Referring to the drawing, Fig. 1 illustrates a preferred embodiment ofmy invention as applied to a switch or circuit breaker with themechanismin the reset and open circuit position; Fig. 2 is a view of themechanism during the operating stroke; Fig. 3 illustrates the mechanismin the operated or closed circuit position; Fig. 4 illustrates themechanism in the tripped or nonoperative position, Fig. 5 illustratesgraphically the design of the mechanism cam for approximating theoperating characteristics of the means to be actuated, and Fig. 6illustrates a. modified form of my invention.

'I'hemechanism illustrated by Fig. 1 comprises suitable actuating meansas a solenoid l which in the present instance is operatively connectedto a movable cam member 2. The solenoid may be of any suitable type andcomprises energizing windings 3 and amov'able armature 4 of the plungertype to which, as at 5, is pivotally connected the cam member 2. Thepivotal connection 5, which constitutes a floating pivotal mounting forthe cam member, includes a roller which is guided for reciprocalmovement in a slot 6 formed in a fixed guide I mounted on the frame 8 ofthe solenoid. v

The cam member 2 is provided with oppositely disposed operating faces 9and ID for coacting respectively with means to be actuated and thetripping means as presently described, the arrangement being such thatas the solenoid armature pulls the cam member upwardly the trippingmeans at the operating face I0 guides the cam member and holds it inoperative engagement with the means to be actuated at the operating face9.

To this end the means to be actuated, comprising in the present instancea switch element as a movable contact arm II, is provided with a rolleri2 arranged to engage the cam operating face 9. The switch arm which ispivotally mounted at l3 carries at its upper end a contact H forcooperation with a fixed contact 15 and is normally biased in opencircuit position as by a tension spring IS. The circuit between thebreaker terminals-at i1 and I8 is completed in the closed circuitposition by the contacts l4 and I5, switch arm II and flexible conductorIS.

The tripping means coacting with the cam face I!) comprises a roller 20carried by a bellcrank 21 having a fixed pivot at 22. The crank arm 23forms with a second bellcrank 24 a restraining toggle. The toggle isheld in restraining position by a latch 25 coactingwith a roller carriedby the crank arm 26. The toggle is held in an underset position by afixed stop pin 21 as illustrated. The tripping force may be applied inany desired manner as by a tripping solenoid 28 having a movablearmature 29 arranged to engage the latch 25 and rotate the same in acounterclockwise direction so as to release the crank 24 and permitcollapse of the toggle.

In the position illustrated by Fig. 1 the solenoid is in the deenergizedposition, the cam member 2 being at its lower position, and the trippingmeans is reset, i. e., the tripping toggle held in restraining positionby the latch 25. The switch arm spring l6 normally biases the roller 12into engagement with the cam face 9.

The operating or closing stroke of the mechanism is initiated byenergization of the solenoid I which results in movement of the armature4 upwardly into the solenoid winding drawing with it the cam member 2.Since the tripping means acting on the cam face l0 guides, by means ofthe roller 20, the cam member and restrains the same with respect tocounterclockwise rotation about its pivot at 5, relative movementbetween the cam operating face 9 and the roller I2 is effective to movethe switch arm l2 in a direc tion' and at a rate dependent on the designof the cam face 9. As illustrated by Fig. 2, the contacts i4 and I5 arein engagement before the armature 4 is moved completely into thesolenoid coilwinding, the cam member during'the operating stroke movinglongitudinally between the rollers i2 and 20 and assuming varyingangular positions by reason of its pivotal mounting 5.

The final part of the operating stroke presses the contacts i4 and I5into high pressure contact engagement for minimizing resistance at thecon. tacts, this part of the stroke being completed in the positionillustrated by Fig. 3. x

The opening operation wherein the mechanism is returned to itsinoperative reset position illustrated by Fig. 1 is effected byenergizing the tripping solenoid 28. This results in releasing movementof the latch 25 and collapse of the toggle 23-24 which no longerrestrains the cam member 2 in operative engagement with the roller l2.Accordingly, the cam member 2 is permitted to swing transversely orcounterclockwise under the bias of the switch spring I! resulting inopening of the switch as illustrated by Fig. 4.

It will be noted, referring more particularly to Fig. 3, that the camoperating face a is provided with a reverse sloping surface at 3'arranged so that the roller II, under bias of spring It, serves to holdthe cam member and the armature 4 in the upper or operated position atthe end of the closing stroke. After the mechanism is tripped, asillustrated by Fig. 4, the cam member 2 and armature 4 drop to the lowerposition and the tripping toggle and latch reset, either under theinfluence of gravity or suitable springs, as illustrated by Fig. 1. Themechanism is now in its reset position in readiness for another cycle ofoperation.

It will be noted that the m is trip-free in operation, i. e., thetripping means can be released at any time during the closing stroke soas immediately to render ineffective the operat ing force on the meansto be actuated. In other words. actuation of the tripping means duringthe middle of the closing stroke permits the cam member 2 immediately tomove in a linear direction and swing coimterclockwise out of operativeengagement with the roller I! so that the reenergy output of theactuating solenoid, the cam face I is so that the combined operatingcharacteristics of the solenoid and cam face approximate those of themeans to be actuated. This will be more clearly understood by referencetoFlg.5whereintheareaunderthe curveAof the force-distance chartrepresents the work required in effecting the operating stroke on themeans to be actuated. In the present instance the closingcharacteristics of a switch or circuit breaker are involved. During thefirst part of the clomng stroke only the frictional forces and springresistance have to be overcome. This part of the stroke is representedup to the point m. At this point the contacts first engage and theopposing ruistance increases greatly as to the point a: due to flexingofthe contacts, as in the case of laminated contacts, and the supportingcontact structure in order to insure high pressure contact engagement.The completely closed position of the contact structure is representedat the point on.

After determination of the amount of work to be done, as represented bythe area under curve' A, a solenoid is chosen the output of which ispreferably of the order of 25 per cent in excess ofthe work required forthe operating stroke. The operating characteristics of a plunger typesolenoid of the character illustrated. are represented by curve B. Thesolenoid plunger travel point b to the end of the stroke representsovertravel of the plunger after the contacts are completely closed andmovement of the cam surface I into et with the roller I! as illustratedin Fig. 3 for holding the cam member and phmger in the upper position.

The curve 0 represents the desired operating characteristics of themechanism since it anticipates curve A. The area beneath the curve C isof course equal to the area beneath the curve B to the point I). Thecurve C preferably provides for a large initial accelerating force forovercoming the inertia of the mechanism.

From thesecurves and by using well known mechanical design methods thecam operating face may be plotted for each increment of travel of thecam member.

In regard to the cam face it cooperating with the tripping means, thedesign preferably is such that the force required to actuate the latch25 is substantially constant. This is generally desirable in view of thefact that the tripping solenoid 28 may deliver a comparatively smalltripping force.

Fig. 6 illustrates a modified form of my invention involving a reversalof the roller and cam members. In this arrangement a roller III iscarried at the end of a link 3i which is in turn pivotally connected tothe guide roller 5. The switch arm II is operatively connected to a cammember 32 having an operating face I! for coacting with the roller Ill.The roller and cam members are held in operative engagement by thetripping means comprising, in the present case, a toggle including alink I! and a pivoted member 34. The members 33 and N are pivotallyconnected at 35 and the link 33 is pivotally connccted at the roller tothe roller actuating link iii. The free end of the pivoted member 34, asin the previous case, is adapted to be engaged by the tripping latch 25which is actuated by the plunger 29 of the tripping solenoid 2|.

When the mechanism is reset with the latch 25 in restraining position(as illustrated by the dotted line position), actuation of the solenoidl is effective to pull the roller Jll upwardly through an are having asits center the pivot so as to cam the switch arm H counterclockwisetowards closed circuit position illustrated by complete lines.

It will be apparent that the mechanism is tripfree in operation sincerelease of the latch 25 during any part of the operating stroke willcause collapse of the toggle 3344, which is shown in an undersetposition, and swinging of the link II and roller 3|! in counterclockwisedirection away from the cam member 32. As in the previous case, the camoperating face I! is preferably designed so as best to anticipate theoperating characteristics of the means to be actuated.

It should be understood that my invention is not limited to specificdetails of construction and arrangement thereof herein illustrated, andthat changes and modifications may occur to one skilled in the artwithout departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. Operating mechanism comprising actuating means and means to beactuated, a cam member, a roller member coacting'with said cam member.and tripping means for holding said roller and cam members in operativeengagement, said tripping means operatively engaging one of saidmembers, the other of said members being separately connected to saidmeans to be actuated, said actuating means effecting relative linearmovement between said roller and cam members for operating said means tobe actuated.

2. Operating mechanism comprising actuating means and meanstobeactuated.'acammem- 7 aoeasss 3 her movable bodily in a linear direction,an element coacting with an operating face of said cam member, saidactuating means effecting relative movement of said element andoperating face in a substantially linear direction so that said means tobe actuated is moved to an operated position, and tripping means forholding said element and cam member in operative engagement.

3. Operating mechanism comprising actuating means, a cam member bodilymovablein a substantially linear direction operativcly connected to saidmeans, means arranged to be actuated by movement of said member in saidlinear direction, and tripping means for maintaining said cam member inoperative engagement with said actuated means during said movement andfor restraining by means of said cam member said actuated means in anoperated position, release of said tripping means causing movement ofsaid cam member away from its actuating and restraining positions.

4. Operating mechanism comprising actuating means, a cam memberpivotally connected to said means, means arranged to be actuated by saidmember, and tripping means for maintaining said cam member in operativeengagement with said actuated members, release of said tripping meanscausing pivotal movement of said cam member away from said actuatedmeans.

5. Operating mechanism comprising actuating means, a cam member movablein a substantially linear direction by said means, said cam memberlikewise movable transversely of. said direction, means arranged to beactuated by said cam memher during its movement in said lineardirection,

and tripping means for restraining said cam member with respect totransverse movement in one direction and for maintaining said member inoperative engagement with said actuated means, release of said trippingmeans causing transverse movement of said cam member away from itsactuating and restraining positions.

6. Operating mechanism comprising actuating means, a cam member, meansto be actuated including a roller arranged to bear on an operating faceof said cam member, said actuating means effecting relative movement ofsaid roller and cam operating face in a substantially linear directionso that said means to be actuated is moved to an operated position, saidcam member movable in a direction away from said roller, and trippingmeans for restraining movement of said cam member in said direction andfor maintaining said cam member in operative engagement with saidroller, release oi said tripping means causing movementof said cammember away from its restraining position with respect to said roller.

7. Operating mechanism comprising actuating means, a cam member movableby said means in a given direction, said cam likewise movable in adirection transversely of said given direction, said cam member havingoppositely disposed operating faces, means to be actuated including aroller arranged to bear on one of said operating faces, and trippingmeans including a roller arranged to bear on the opposite operating facefor restraining movement of said cam member in a direction away fromsaid first-named roller and for maintaining said cam member in operativeengagement therewith, release of said tripping means causing transversemovement of said cam member away from its operating and restrainingpositions.

8. Operating mechanism comprising a solenoid, a cam member movable in agiven direction by said solenoid, means to be actuated, said cam memberhaving an operating face coacting with said means to be actuatedcharacterized in that the combined operating characteristics of saidsolenoid and cam face approximate those of said means to be actuated,said cam member likewise movable in a directionaway from its operatingposition with respect to said means to be actuated, and tripping meansfor restraining movement of said cam member in said last nameddirection, said cam member likewise having an operating face coactingwith said tripping means characterized in that the tripping force atsaid tripping means is substantially constant.

9. Operating mechanism of the trip free type comprising a solenoid, acam member movable by said solenoid in a given direction, said cammember having operating faces at opposite sides thereof, means to beactuated including a roller arranged to bear on one of said operatingfaces, and tripping means including a roller arranged to bear on theopposite operating face of said cam member for maintaining said cammember and first named roller in operative engagement, actuation of saidsolenoid causing longitudinal movement of said cam member between saidrollers, release of said tripping means at one side of said cam memberpermitting movement of said cam member out of operative engagement withrespect to said first named roller.

10. Operating mechanism of the trip-free type comprising a solenoid, acam member pivotally connected to said solenoid, said cam member havingoperating faces at opposite sides thereof, tripping means including aroller arranged to bear on one of said operating faces, said trippingmeans normally guiding in a given direction said cam member when thesame is actuated by said solenoid, and means to be actuated including aroller arranged to bear on the opposite operating face of said cammember movement of said cam member in said guided direction causingmovement of said means to be actuated to an operated position, releaseof said tripping means causing movement of said cam member to anon-operating position.

11. Switch operating mechanism of the tripfree type comprising asolenoid having a plunger, a cam member connected to and bodily movablein a given direction with said plunger, a switch element movable to openand closed circuit positions, said cam member having an operating facecoasting with said switch element characterized in that the combinedoperating characteristics of said solenoid and cam member approximatethose of said switch element, said cam member likewise movableindependently of. said plunger in a' direction away from its operatingposition with respect to said switch element, and tripping means fornormally engagin and restraining movement of said cam member in saidlast-named direction.

